1. Field of the Invention
The present invention relates to a detector assembly or detector block that can be installed as the sensing element in an electromagnetic induction-type conductivity meter wherein electrical current is caused to pass through a liquid sample by an electromagnetic induction and detected by a detector coil to measure the conductivity of a sample. More particularly, the invention relates to a relatively compact and self-contained detector assembly for accomplishing such a measurement.
2. Description of Related Art
It has been known to utilize an immersion-type conductivity meter wherein the actual detector element or sensor can be immersed in the liquid sample within a liquid tank and/or a reaction tank. It has also been known to use a flow-through-type conductivity meter for connection to a pipeline in which a liquid sample passes. In such meters, a detector element is usually mounted in such a manner that the sample may flow through the detector element. These types of meters have been generically known as electromagnetic induction-type conductivity meters.
Generally, electromagnetic induction-type conductivity meters, such as those described above, are relatively large in size and can cause problems in their specific applications. Particularly in the immersion-type conductivity meter, it is frequently necessary to increase the total length of the meter and to adjust that total length, depending upon the level of liquid surface within which the detector element is immersed, particularly in large-size liquid tanks. With regard to the flow-through-type conductivity meters, there is usually a requirement for providing a flange and a holder for mounting the detector element at a midway position relative to the pipeline. Such additional features can significantly increase the cost of the meter.
An additional problem frequently occurs in both the immersion-type conductivity meters and the flow-through-type conductivity meters in that an excitation coil and a detection coil are utilized as the active portions of the detector element, and they are coated within a thin-walled resin or the like to protect it from the sample fluid. These coatings can cause a problem in increasing the difficulty in manufacturing the meters, and can cause a possible problem of liquid leakage if improperly prepared.
Accordingly, there is a demand in the prior art to provide a highly efficient and compact electromagnetic induction-type conductivity meter.